1. Field of the Invention
The present invention relates to a fringe-field-switching (FFS)-mode liquid crystal display (LCD), which increases an aperture ratio and an internal reflectance to improve outdoor visibility, and a method of manufacturing the same.
2. Discussion of Related Art
In general, a FFS-mode LCD has been proposed to improve the aperture ratio and transmittance of an in-plane-switching (IPS)-mode LCD.
A FFS-mode LCD may include a common electrode (or counter electrode) and a pixel electrode, which are formed of transparent conductive materials, to increase an aperture ratio and a transmittance compared to an IPS-mode LCD. Also, a distance between the common electrode and the pixel electrode may be controlled to be smaller than a distance between upper and lower glass substrates so that a fringe field can be formed between the common electrode and the pixel electrode. Thus, every liquid crystal (LC) molecule present on the electrodes may be operated, thereby improving a transmittance.
Conventional FFS-mode LCDs have been disclosed in, for example, Korean Patent Nos. 341123, 855782, and 849599 filed and registered by the present applicant.
Looking at some of the above-described Patents, Korean Patent No. 855782 discloses a FFS-mode LCD including a transparent common electrode and a transparent pixel electrode disposed over the transparent common electrode with an insulating layer therebetween. In the FFS-mode LCD, a direction in which a LC layer is rubbed may be within 5° based on a direction of a gate line, one end of the transparent common electrode may be disposed between a data line and the transparent pixel electrode, and a distance between the transparent common electrode and the transparent pixel electrode may be controlled based on the data line to improve an aperture ratio and a light transmittance around the data line.
Also, Korean Patent No. 849599 discloses a FFS-mode LCD in which the widths and arrangements of a data line, a transparent common electrode and a transparent pixel electrode around the data line are controlled such that LC around the data line may be driven in a different LC drive mode from LC drive mode in the center of a pixel region. Thus, a light shielding layer formed over the data line may be removed, and light leakage may be prevented.
The FFS-mode LCDs disclosed in Korean Patent Nos. 855782 and 849599 may increase outdoor visibility and an aperture ratio and enable low-power operations. However, some problems to improve performance still remain unsolved.
First, a margin required for alignment with upper and lower plates may be reduced due to reduction or removal of light shielding layers. It may cause a mixture of colors, and thereby increasing a failure rate. According to Korean Patent No. 849599, rubbing may be incompletely performed in a stepped portion of a data line. From this incompletion of rubbing, light leakage may occur in the stepped portion of the data line, especially data line side of opposite to rubbing direction.
Accordingly, it is still required to develop a new FFS-mode LCD to solve the above-described problems.